Video contents by timestamp: 00:06:40 - Introduction 00:15:05 - Reactivity problems for Helion 00:30:57 - Helion will have 14MeV Neutrons 00:43:50 - The problems with Neutrons 01:05:52 - Helion's difficulties with Neutron shielding 01:18:57 - Why tokamaks etc might be better 01:28:28 - Diagnostics issues/discussion 01:42:00 - Turbulence + issues with Helion simulations 01:55:14 - Fast ion issues for Helion 02:02:26 - Adiabatic energy conversion issues for Helion 02:18:33 - Miscellaneous discussion 02:30:00 - NIF recent results discussion 02:42:23 - Outlook for Inertial Fusion power 03:03:08 - UA-cam channel meta discussion 03:06:00 - Lattice fusion summary 03:09:40 - More meta + AI for fusion
I fell asleep listening to UA-cam videos and now I woke up in the middle of this video and have absolutely no idea what it's about. Seems like a good video though
Cringe... that's what I sound like when I can't edit the million breaths, "uhms" and "you know"s? 😵 I thought it sounded OK during the stream, but listening back the audio and my speaking manner is just dreadful. Sorry about that.
When you are on a topic your speaking manner is quite good and easy to listen to. Sometimes you looked at comments in between and it completely disrupted your sentences. I think some little structural changes to the Q&A format could keep the contend and the questions from interfering. Anyways, I loved the commentary on how exactly Helion has to speedrun a couple of decades worth of fusion research to even get their equipment up to date.
Great discussion of some of the engineering problems of fusion systems. I wish the companies were more forthcoming about these issues. Mostly they either hand-wave or say nothing at all. Thank you!
This was fantastic. I really hope you continue making more content. This chat was a nice way to provide deeper coverage than your higher production value slide-deck style videos. It's really nice to hear from someone who knows what they are talking about.
To be fair, while Tritium is very radioactive (decay rate), the beta decay energy of Tritium is very veak, in the KeV range, so the electrons coming off it will quickly slow down, provided they come from outside the body.
Consider the outcry over the release of a few grams of Tritium in waste water from the Fukushima plant. Helion intends to keep kilograms of it in storage. Note that this is much higher than a D-T plant, since that would basically be cycling it very rapidly, not storing it for years waiting for it to decay.
Thanks for the great presentation! As a student in a DOE neutron scattering facility, I think many people are underestimating the regulatory hurdles that come with radioactivity from neutron activation. Also, I'm really curious about your take on general fusion. Their design seems to check a lot of your good-fusion-engineering boxes while being very different from a tokamak. Would you consider doing a video looking at their approach?
Sorry I couldn't join. Thanks for the kind words. Try'n make it next time. Just to clarify, I definitely don't have a PhD, and I'm at LLE rather than NIF. Just a lowly optics engineer, lol.
@@ImprobableMatter Incidentally where did you watch that movie Девять дней одного года? On some streaming service? I can't find an english subtitled version anywhere.
@@Muonium1 Firstly, I there used to be a version with good subtitles on UA-cam, but it has been deleted. Secondly, I believe I have a DVD which also supposedly has subtitles, but I will have to dig that out. It's quite good; it's not satirical like "Strangelove", rather very honest and actually has good science.
@@ImprobableMatter For all the boundless loathing I have for Soviet socialist-communism, I have to say that I do have a near equal measure of respect for the quality and resourcefulness of their physics during that era.
I really appreciate this it was very informative. Next time you do a Q&A, can you please read the questions out-loud before answering them? Sometimes, I was not sure what criticism exactly you were responding to.
at around 1:04:30 you are comparing a required 10^25 neutrons to cover 10 square metres and shred it the same as those mirrors, with their estimated 10^18 neutrons per second. This gives you 10^7 seconds to get that many neutrons. But then for some reason you change your answer to 10^5 seconds, and say that it will take a day, whereas with these numbers it should be 100 days. Now, I'm not saying that any of these estimates are necessarily correct, and it's probably a lot worse, but just introducing factor of 100 errors in your simple calculations does tarnish the reliability of your general statements about how bad it would be. I think it's worth checking the calculations before making statements, not because the results are much different, but because it makes it appear more reputable.
Love, love it Great video about the challenges of Fussion I love how each problem is being broken to fully understand the issues moving forward Keep the good informative job !!
A lot of things (incl proofs of concepts for any fusion project) can only be revealed & clarified & adopted during live experimentations that's once first production size facility (v7 for "Helion Energy") will be built.
Regarding lattice confinement fusion, there was a UK company called Positron Dynamics that claimed something similar to NASA, well before them, using positrons from beta decay to induce fusion in a deuterium saturated lattice. A lot of their work was about slowing down the hot positrons.There are some videos around and even got a NIAC grant. The idea was to use it for propulsion. If I remember correctly, they used the beta positive decay of a Krypton isotope and wanted to use the neutrons produced during fusion, to make more beta positive decay isotopes. I haven't heard from them for a quite a while though, so maybe it's not working very well for them.
Good stream, I think very fair discussions and descriptions of the challenges. Donating to keep this kind of content coming! Maybe I can join on the next stream and ask about p-B11 reaction concepts if you're interested given the economics might be more workable.
I think it's safe to say that the only thing this channel has in common with Thunderf00t is a slight similarity in speaking voice. Thunderf00t main argues from a perspective of ignorance and has very little understanding of how the engineering process work e.g. criticises prototypes for being prototypes.
Thank you for taking the time to do this stream. If you do another Q&A (I hope you do) it would be great if you had better audio for your friend, I found them quite hard to hear / understand.
For the AI related question that you answered at 3:10:50, you did briefly touch on AI-driven design, but then focused more heavily on uses of AI for solving operational control problems. I generally agree with your "no silver bullet" comment; most people thinking that way don't have a firm understanding of the subject. In the case of AI-driven design, it's less about "machines being smarter than human designers", and more about "machine having the processing throughput to manipulate designs that are orders of magnitude more complex than human brains can manage". Humans are strategically brilliant and can make it very far by simplifying designs to the point where they are comprehensible by our relatively slow brains (to grossly oversimplify, very little in our brains moves quicker than 100Hz). The AI-optimized mechanical designs typically find savings by producing complicated flowing geometries that appear almost organic in style. In a crude sense, the difference between AI-optimized vs human-oriented designs is analogous to the stylistic difference between the complex Stellarator geometry versus the more regular Tokemak geometry -- and I suspect this observation may have inspired the question you were answering. In the case of optimizing a Stellarator, to predict the degree to which AI-driven design optimization would help, I'd need to have experience grappling with the Stellarator optimization trade-offs, to know the extent to which competing trade-offs interact in such a way that increased complexity can deliver improvements in the performance metrics. In other words, AI won't help if it's the case that the seemingly complex Stellarator shape is actually rather regular (eg, a consistent degree of twist from coil to coil), and if there's very little optimization incentive to mutate that shape. On the other hand, if there are a lot of interacting considerations and a vast potential design space, then maybe there's more headroom. It might also be interesting to open up the design space by disaggregating the coils into a messy spaghetti of individual wires that can wrap the reactor at more than one angle rather than all loops from the same wire being parallel. Again, I'm not qualified to say where the Stellarator design headroom lives, or how much might exist; I'm just giving examples of the kinds of design changes that an AI-driven optimizer could explore. Such AI-driven designs are intrinsically more challenging to fabricate, and for mechanical designs, depend heavily on being able to leverage digitally controlled additive and subtractive manufacturing techniques (eg 3D printing). One of the challenges of applying such techniques to a Stellarator would be the increased assembly cost. You might need a custom robot to lay the wires in a wildly complex geometry, or you'd have to have people following incredibly detailed instructions that resemble the (very expensive) custom-cut carbon-fiber hand-layup work done for turbofan blades ($20k per blade). And then the design would be highly brittle / difficult to change / difficult to repair. And it might be exponentially more difficult for the physicists to model (this alone might be a deal-breaker?). AI-driven design optimizers can of course incorporate fabrication constraints or estimated fabrication costs into their optimization goal function, but such constraints would need to be expressed formally rather than simply being designer intuitions and getting that right might take several iteration cycles between the physicists and their AI collaborators. I don't know if this has been explored or not, but the first step would be to prove that there's enough optimization headroom to matter by producing a theoretical design that boosts the predicted optimization parameters (confinement time? field strength?) by a material amount, without worrying too much about whether or not the result is practical and buildable. If you can't produce a predicted win even from an unbuildable design, then there's no point in worrying about the practical problems. But if early exploration demonstrates large potential headroom, then researchers could explore constraining the AI's design space such that it can produce a good compromise design that boosts the optimized goals as much as possible, while still being constructible and practical enough on the other figures of merit (maintainability, repairability, modularity, etc). Everything above is my mental model as someone familiar with training AI systems. My question to you is to answer what I cannot: does your instinct say that the Stellarator design shape could be improved via increased complexity? Can I (or an AI) take the existing design, and find incremental improvements by tweaking some of the coil shapes? Or is the design already close to optimality given present materials constraints, and the only thing that would help is a gross improvement, such as stronger superconducting magnet coils, or an increase in scale? What does your intuition say on this?
Wish I'd known this was a live qa I just took plasma physics & fusion reactor design principals at UMich. Going to take take the part 2 and grad lab soon. So i have a lot of questions. A lot of the helion guys went thrift this program, for better or worse.
Ok so the first graph shows the amount of temperature produced which is not how Helion's reactors generate energy. They are not trying to heat up water to turn a turbine, temperature is not relevant to them. I thought real engineering explained it well but looking at the responses you got I can see that few understood and argued on your terms based on your misunderstanding. Its this part of the video ua-cam.com/video/_bDXXWQxK38/v-deo.html
This is highly enjoyable to listen to such a discussion, I applied to work as an apprentice at JET a long time ago but was unfortunately not successful due to the IAEA. Still find the subject interesting. Hard problems are fun
Question: What prevents Tokemak (or Stellarator) designs from increasing the field strength by simply using more turns of magnet wire? In other words, today the magnet coils wrap around the reactor N times to create some field strength B. What limits designers from scaling this to wrapping the reactor 2N or 10N times? Or equivalently, putting a second coil surrounding the existing coil? The outermost coils would have a wider diameter, so IIUC, would be less efficient at contributing field strength, but presumably they would still be helpful. Or are the designs already physically constrained, such as by the space to run wires through the center column? Or is there a more subtle magnetic constraint that I'm not aware of? Or maybe it's just a cost limitation and rather than doing as I suggest, they'd rather spend the equivalent funding increase scaling up to a large Tokemak (ie, scale everything together).
One might think that a superconductor would have anywhere up to infinite current for a given voltage, but there is a maximum magnetic field at which they no longer work. Also, really huge fields would put enormous mechanical stresses on the machine.
I appreciate that you aim to use less rude notes on your words. Gasoline is more reactive than jet fuel, but jet fuel have more energy per reaction. I think that's a better analogy
@@ImprobableMatter yes because you need more sunflower oil molecules. Gasoline is high (energy) density high reactivity, and jet fuel in comparison is even higher density but low reactivity. while cooking oils have low density and low reactivity.
@@ImprobableMatter Could we have a stand-alone video like your normal ones, on the topic? Also, can you tell us the number of barns and eV for that reaction? And from what I understand He3 does react with itself, would that be also a part of the "Catalyzed D-D + D" fuel cycle?
Thank you for your detailed presentation. I have to wonder if the Helion approach of electricity generation by driving the magnetic flux out through the coils via the expanding plasma can be done with decent efficiency. Decades ago, people pursued magnetohydrodynamic generators as an alternative to traditional turbines driving traditional electromagnetic generators. I think these efforts failed because the combustion gasses could not be made sufficiently conductive to achieve good efficiency. Also, people have built explosive generators to produce very high pulse electrical power, but these generally expand a good conductor such as a copper cylinder to efficiently drive the magnetic flux through the coil. In the Helion process, how much of the flux can the plasma drive out? How much of the energy escapes as heat and neutrons in the process? Regarding your graphic for the National Ignition Facility, extrapolating to a net electrical gain of 10 MJ per shot: 10MJ is about 2.8 kWh of energy. I am paying about 12 cents per kWh (retail price for electricity delivered all the way to my home). So, the energy from a shot is worth about 33 cents delivered. Perhaps the generating facility could be attractive if it could produce the energy at half that cost, or about 16 cents per shot. Suppose the diamond spherical shell for the fuel could be eliminated as well as the hohlraum, and the lasers could simply impinge directly on cryogenically frozen fuel pellets. Do you suppose the tritium-deuterium pellets could be produced at a cost of a few cents each, given that the facility would consume 864,000 pellets in a day of full operation at 10 shots per second? If we ignore the window material darkening issue, how many shots can be done before the laser window surfaces in the reaction chamber must be cleaned due to deposition of materials liberated from the chamber walls and equipment in response to the bombardment of the reaction products? The energy released in each shot presumably ends up as heat in the chamber walls. Given the size of the chamber (about ten meters in diameter) to stand up to the ongoing mini-explosions without fatigue, it would seem to be thermodynamically difficult to capture the heat at high enough temperature to achieve any conversion efficiency to electricity approaching 60%, let alone maintaining laser beam aiming accuracy to within a few tens of micrometers or better to assure uniform implosion. It is presumably very difficult to recycle the energy dissipated in the lasers themselves and that energy presumably ends up as additional waste heat (unless the facility is in a cold climate where the waste heat can be used for other purposes.) I'm just trying to say that a facility with net electrical energy gain may still be a long way from a commercially viable energy generation facility.
In principle, energy from the expansion of Helion's FRC could be recaptured as efficiently as the contraction. However, energy would be lost as bremsstrahlung, due to turbulence and the energetic particles produced by fusion with relatively large gyroradii. Also, they are going to be charging capacitors, which would have to remain efficient at high rep rates, working for months on end, and with the neutron/radiation issues I mentioned. Could a laser direct drive scheme reach commercial viability? You raise very good points for why that would be a challenge. Certainly, if everything else were viable, pellet production costs would come down, but it's true - the final product cannot be made of gold or diamond or it will never compete with other power sources.
So this thing shoots plasma in, compressed, fusion reaction, shoot into a MHD converter, ok so Helion Energy’s reactor is being sound more like a glorified Z-pinch.
You showed a study on neutron-induced damage which used 0.01 MeV neutrons. And then said Helion would be dealing with much larger energy neutrons, implying that higher energy automatically equals more damage. But I thought the probability of a neutron interacting with a material (depending on the particular interaction process that is causing the damage) can be strongly dependent on the energy, and that for some processes, a high energy neutron is much less likely to initiate an interaction than a slower neutron. Can you comment on this? Given some reasonably expected types of neutron damage (what processes can happen that cause neutron-induced damage to steel, copper, silicon, etc...?), will the neutrons being higher energy increase or decrease the probability of the underlying interaction processes? You didn't even identify the particular process referenced in the study, and do a quick check to see if that process is more or less likely at higher energies. You just made a straight assertion that higher energy always equals more damage. Maybe it's obvious to you with more background knowledge than me on this topic, but it isn't obvious to me or probably most other viewers.
I motivated why they will necessarily have 2.4MeV neutrons and why they will almost certainly also have 14MeV neutrons. First of all, the exact effects of a huge neutron flux on technologically relevant materials is not well understood - this is why the rest of the fusion community are doing research as shown in Reference [6] from as recently as last year. The only certainty is that fast neutrons are bad news for the absorbing material. Secondly, the study I showed (Reference [5]) had both thermal and >0.1MeV (potentially up to 2MeV or higher) neutrons. It is true that the absorption cross section is different for different energies, but eventually a fast neutron will collide and give up its energy (forget for an moment transmutation reactions) with part of the Helion machine. The more energy transferred, the worse it is for atoms which were previously sitting neatly in a lattice.
I think the neutron issue is more than anyone can think of. At least I haven't seen any comment mentioned the role of NRC. Since you are operating a power plant that emit radiation, you need to get approval from NRC before operation. Even if they do make it work and commercially feasibe, I am quite confident that they will never get pass NRC. NRC may take ten year to aquire the knowledge required to regulate this type of power plant. Then take another ten year to verify your design, material and operating procedure.
So several years ago I was at a bar with an employee from helion. In talking to him his opinion of the company and it’s goal was that the major problem was not the plasma physics, it was that the solid state power switching required to harvest the induced current in the magnets didn’t exist yet. So from him (at least this is my fuzzy and incomplete memory) they were already generating sufficient energy output, they just couldn’t harvest it. I don’t know if the power switching problem has been solved or if this adds to the conversation but it may be that the inefficiencies and limitations that you are worried about are solved but another practical issue is still limiting the overall technology
So I keep being on the side of "let's avoid neutrons", and as far as I understood that means proton-boron, right? So, if we figure out plasma confinement, what would be the limiting factor to temperature? The Bremsstrahlung? What if, in theory, we could harvest the power from Bremsstrahlung? Would the problem then basically be that the amount of energy dissipated by Bremsstrahlung is not related to the amount of energy created by fusion? And then the plasma would end up cooling down?
Yes, the problem would be bremsstrahlung, and the problem with the losses through it is that they would have to be recovered by steam turbines. Let's call the latter 50% efficient; if during a given interval of time you emit 100J of energy as bremsstrahlung, you have wasted 50J as heat. You must then make sure you are doing fusion quickly enough that you make back the wasted 50J. If you are extracting the fusion energy through steam turbines as well, then you have to make 100J. Numbers out of my butt aside, serious studies on this have concluded that this is hard.
@@ImprobableMatter Ohhh! So the energy balance would be reached by dumping the excess energy extracted back into the plasma. Which, both extracting energy from Bremsstrahlung and putting energy back into the plasma is inefficient currently. Got it, thank you!!!
@@ImprobableMatter Yea, I know, but maybe in a few centuries we figure out how to make really efficient photovoltaics or something, I don't know 😃 Edit: Or is there a theoretical limit on those also?
Re: the adiabatic cycle - isn't the initial heating to 1MC and the fact the final plasma is at the same 1MC a good thing? 1. Heat plasma to 1MC 2. Magnetically compress plasma to 100-200MC 3. Fusion occurs heating plasma to much greater than 100-200MC 4. Expand of plasma and extract work (magnetically/somehow) back to 1MC plasma 5. GoTo #2 What am I missing? Is the plasma at #4 an "exhaust" carrying away the energy put in at #1 so #5 becomes "GoTo #1"?
My point is that after #5, you have to cool it down to room temperature. Otherwise, you can't pump out the Tritium gas (discussed why that is bad) and add new fuel. In any case, the way they described it, it will hit their divertor and cool anyway.
Very good point: fusion Neutron/MeV is 1/20 vs 1/72 for fission … so any RFC using this fuel will produce “a reactors worth” of radiation ie if u got to supply 250MeV then u got lots of coulombs of fast neutrons ❤ great point bro
Genetic algorithms are a sub-set of AI. Or at least they were when I was studying it (some decades ago). Perhaps you meant to say "as opposed to any other kind of AI"?
I think the Q&A was better than the original video and had a nicer tone too (at least in the parts that I was there for). I talked to David Kirtley about your argument about T- scattering and disruptions. He says, he might put together something for the FAQ if they have the time. Their electron temperature diagnostic was vetted on TFTR, btw. They also measure the plasma pressure on all locations. They also have the usual standard diagnostics for FRCs that have been vetted on every FRC program since. Overall, their diagnostics should be better than NIF. The disruptions argument has been brought before but they have not materialized over 6 programs that went all the way to 10 keV today. I think it is unlikely that disruptions will suddenly appear at 20 out of nowhere. But what do I know? The original video though... Oh come on! Just the part about "Helion promising a working power plant by 2021" is easily debunked as a factual error and quite frankly really unfair. It even says on the same page that you quoted (and show in the video) that they were looking for funding! They did not have the funding until very recently. No bucks, no Buck Rogers! Most of the other points are either not applicable or lack context, etc. I think you are a really smart dude, who does know a lot. So I will say again, that I am extending my offer to have a serious debate about this, if you actually want that. I can (likely) get you answers to questions if you are interested.
@@elmarmoelzer2229 I didn't talk about disruptions, I talked about turbulence and fast ion losses, both of which CYGNUS does not and cannot simulate directly. Also, neutron embrittlement of their machine, their inability to pump out trace amounts of tritium with 1+Hz duty cycles leading to 14MeV neutrons and the inability of plasma below ~100eV to be used in the adiabatic cycle, hence that energy is unrecoverable. A few other things as well.
At 2:58:42, you claim that any commercially sized pulsed ICF approach (ex. >4000 MW) must fire multiple times per second. You reasoned that slower pulsing requires larger yields to produce the equivalent amount of power, and, by analogy to high-explosives, “nothing could survive a ton of TNT.” However, TNT is a chemical explosive. Most of the energy in DT fusion goes into the 14.1 MeV neutrons which penetrate several centimeters before thermalizing. Compared to chemical explosives, which are millions of times less energetic than nuclear reactions, a DT fusion reaction of equivalent energy (m*v*v/2) would produce thousands of times less outward directed momentum (m*v). Hence, it could easily contain much higher yields. Does this make sense?
Fair enough, but the near-instantaneous energy absorption is still difficult to handle and there is a limit. The target chamber at NIF is 10 meters across and is supposedly limited to a maximum yield of 45MJ only, see page 4 of the following: www.osti.gov/servlets/purl/15006532 Momentum aside, I think regular cyclic loading of a tonne of TNT of energy released in nanoseconds is out of the question for a practical facility.
@@ImprobableMatter OK, but NIF is not a commercial power plant, so it is not a good example to use for determining the maximum withstandible yield of a commercial power plant. NIF does not protect its optics from the intense neutron/x-ray pulses or flying debris, so damage accumulates each time a target is ignited. In that light, I understand the 45 MJ maximum yield you quoted. A more robust example (closer to the maximum) can be found in Freeman Dyson’s analysis of The Orion, a nuclear pulse rocket designed for missions to Alpha Centauri, the nearest star system to the Sun. His 1968 paper "Interstellar Transport" (Physics Today, October 1968, pp. (41-45) suggests how to fly city-sized spaceships by detonating megaton-sized deuterium fusion explosions in their proximity. For a less extreme example, in PACER revisited, R. W. Moir discusses an idea to generate electricity by detonating 2kt hydrogen bombs in an underground cavity lined with steel. His idea uses molten salt (FliBe) to absorb the neutrons and x-rays. Does that make sense?
@@michaeldeeth811 Yes, the idea of making energy by detonating thermonuclear bombs is not new. It would simply not commercially viable. These are old speculative paper studies and NIF is engineering reality. If you want to extrapolate to a practical powerplant, I would suggest the latter and not the former.
@@ImprobableMatter In clarification, I was not advocating for PACER or Orion. They were used as counterexamples, opposing the 45 MJ maximum yield boundary you imposed on ICF. It is ironic that you called NIF an example of non-speculative engineering. NIF was an extremely speculative design, two orders of magnitude beyond NOVA (at that time the world’s largest laser). Anyway, I started this thread because you said commercial IFE requires multiple shots per second. You based that on a maximum yield limit, stipulated to be 45 MJ. Do we agree that the 45 MJ maximum yield stipulation, applicable to NIF's unprotected optics, is not suitable for IFE in general? If so, the statement about IFE requiring multiple shots per second is unjustified. Am I making sense?
@@michaeldeeth811 I'm happy to lift the 45MJ limit by maybe an order of magnitude, but not the stipulation that IFE requires at least 1Hz rep rate to be practical. Not because I think I'm super clever - far from it - but because this is the consensus reached by scientists in the field, for the reasons I described.
You could certainly fiddle with different materials to optimize the neutron shielding, but at the end of the day (A) Helion's current design does not leave enough room to shield the coils; (B) the plasma-facing material will become churned up and retain Tritium therefore making it radioactive and contaminating the D-3He plasma with a producer of 14MeV neutrons.
Dots in a jell of clear liquid shape to the densities around themselves when you are pushing them to a 90 degree bend and then another one will change the way you think about what is happening
Awesome stream, very interesting content, glad to hear professional and realistic take on fusion. IDK, but I feel in the gut (or rather ass) that NIF has the highest probability of success, just due to the fact that military also benefits that. Sounds like the same story like with fission :)
Mh not sure about that, being military funded, they focus on simulating what would happen in a fusion bomb (geometry and stuff). They could get already much better fusion yields, but they'd have to reconfigure all the lasers, which wouldn't benefit the military, so it isn't going to happen
NIF has zero chance of success. None. 0.00000% chance. In order to generate electricity as a power plant commercially, they need to fire several times in a seconds. They can manage only one or two per day. The target pellet needs to be manufactured perfectly and aligned perfectly. How can you load a pellet several times a second with nanometre precision? It won't scale. Thus it is just a scientic experiment and with great military value. Remember the name, National Ignition Facility. Ignite what? Hydrogen bomb, men.
A video titled "What This Breakthrough Means for Nuclear Fusion" by Undecided with Matt Ferrell, shows that 200MJ of power created 2.05 MJ of Laser energy, from which 3.15 MJ of fusion energy was produced at the NIF.
That's great. It does work. Thermonuclear bombs work too. However, it's no where near practical. The physics says it can be done in a myriad of ways but the engineering needs to close that gap before there any hope of a functioning reactor. Personally, my favorite idea is liquid metal cavitation because it's the neatest engineering setup. Nothing but NIF has been demonstrated but NIF is never going to be a practical method by its very design. A completely different idea which borrows its concepts might work.
I love your content but I think you are being way too "fair". There is a whole economics around startups and venture capital. The real purpose of many startups is to get bought out by someone bigger - so the founders become rich. Similarly Venture Capitalists may not care about the longevity or practicality of a startup - they care if the startup will attract more investors so they can sell their share and make money. The entire financial industry is built on trends and speculation on those trends. The long term sustainability is irrelevant. As to Real Engineering - the guy has 3m subscribers but its all "The Insane Engineering of the !!" - clickbait for people who can't tell the difference between science and science fiction. Looking at the video its pretty much an uncritical promo. To be fair that is how science is mostly reported across the MSM. Its incredibly sad that well researched well explained factual info get trumped by marketing drivel.
BTW, doesn’t that guy realise that tokamaks could use direct energy converters as well, such as nipping electrons from the plasma donut and run it through a inverse cyclotron converter.
Great video. Thank you There’s all this talk that “with a liter of heavy water we could power Boston for 100 years”. Can u help me understand or point me to something that would explain how much fuel is in the chamber? do they inject the fuel once then let the machine run? How much fuel? Is there a limit on how much fuel? This would be for a tokamak
Also, what is the number 1 obstacle to self sustaining fusion? Magnets? Metals? Product? If we had magnets that held temperatures of 600 million, could we go straight to the next problem? Or is it the plasma drift problem? Where the plasma seeps outside the field?
I've read some comments to this video claiming they prefer your scripted ones, mainly because those are easier to follow. In the case of the critique of Helion's claims/ideas/machines I have to disagree, this one is much better. In my opinion, reasoned, well informed criticism is always better than rushed derision. This one sounds a lot more like scientific debate, less "ranty". Here you offer a number of interesting, reasoned points that were not that well argued/justified in the previous one. Pity this only has 1/50 the number of views. Maybe translate this one into a script for a shorter, clearer, third try ? P.S. Given the increasing number of startups in the field of fusion power, someone with the required knowledge could start a series of scientific critiques of them. Just saying. 😉
You definitely could use vegetable oil as rocket fuel. You do know RP1 is pretty much just deisel fuel right? High enough amounts of oxygen will make steel burn like a rocket fuel
The gun analogy is not particularly helpful, a fusion powerplant is only producing and absorbing energy at comparable levels to a non fusion plant in a gas turbine we might be putting 200MW of heat energy into a combustor that would fit in a coffee table.
To further elaboration on the shell analogue. Shells are specifically designed to produce a damaging effect in a way that is difficult to mitigate. They contain the explosion in such a manner that it transfers energy to solid projectiles, the shell can penetrate targets so that the explosive pressure can be used to split solid objects. A more reasonable approximation would be the gun itself. In that context explosions may be contained in the breach and provides you provide adequate cooling a high rate of pulsed energy depositions can be contained.
Yes, but my point is the cyclic nature of it. For any proposal, ask yourself: can all the systems cycle at the proposed frequency? Lasers, electronics, pumping, capsule injection, capsule manufacture etc... In principle yes, but not so easy. My two cents are at the end of my inertial fusion discussion: ua-cam.com/video/mxmxZI2Ltvs/v-deo.html
I completely disagree with you on the nature of Thunderf00t. His videos have been fairly reliable as a whole and so far none of them have ended up contradicted by reality. The only one I think is slightly off the mark is the idea batteries can't get much better than they are, even theoretically sulfur batteries would be better than lithium if we can find a way to make them stable, but as a whole none of them has been inaccurate. I will say his old feminist and creationist videos were crude, but saying it's "splitting hairs" is a pretty bold statement when the creationist videos are literally a mirror of what philosophers have been saying for the last 2000 years and very few people have agreed with be vocal modern feminists (to the point all of them from the time he made those videos have become irrelevant). But most of his videos go directly into the math on why the claims made are untrue. That's about as reliable as your argument could be. The most I could find that could be argued is a reddit post about his Space X videos, though the retorts aren't any less hair pulling than his and a few contradict other arguments they made. There's only one claim of his that was wrong and it's more because Space X said it themselves internally. They sent emails saying if they couldn't find a way to reuse the same rocket every 2 weeks they'd go bankrupt. In reality neither happened, they never got relaunches that fast nor have they gone bankrupt. Though they did raise launch prices and have been receiving grants from the government so that's more likely why they believed such.
Heh. Trying to talk to fusion fanbois is like talking to MSR fanbois referencing Oakridge. Fusion will get worked out but the when is an unknown even with the half dozen different concepts out there where the maths but only the ideal maths checks out.
I want to study nuclear fusion in college, is nuclear fusion feasible? Is what I am trying to do a waste of time? If I can't make a living doing nuclear fusion research, I plan to join another university where I can make good money. Is there a future for nuclear fusion research?
how is anybody suppose to know for sure? theyre still working on this... what im pretty sure about is that it will take more than one man and many metric tons of money to get it done... so yeah somewhere in there there is room for you as well... it will look something like a stadium shot but it is what it is
I think you should consider transferable skills and personal growth more than just "where I can make good money". imo fusion will stay around for research for a long time but its not what I'd call "stable". You might move jobs quiet a lot depending on where you go. ITER will be around for a long time for example. Just in general if you're good enough to be a Fusion Nuclear Physicist or Engineer you can do ALOT more in any other topic you please. And a good understanding of engineering and/or physics makes good foundational knowledge for other things. Say, aerospace and silicon.
You can make a living doing anything, and Dennis Whyte's discussion on the industry of fusion research with Lex Fridman indicates that there will be an increasing desire for fusion reactor engineers and scientists going into the future. We can do nuclear fusion research, and its interesting and important to a lot of parallel human endeavours. This question, however, often is conflated with "can we do nuclear fusion in a plant on earth such that it generates power on the order of GWs into a cities' electrical grid AND so that it is competitive on the energy market". This, unfortunately, is not really guaranteed. It's possible that this is the equivalent of building a space rocket to get you from your home to your school. It might generate more force and do the job faster, but the technological complexity and scale required to simply get it to turn on might be so beyond what you actually need. So that may mean that every power plant costs ten times what a fission plant would cost, and 100 times what solar/wind and other sources would cost even with scaling economics. Its highly doubtful that nuclear will be a significant component on the switch from hydrocarbon energy sources anytime soon, as reiterated by a number of nuclear regulatory leaders. I would assume this includes fusion for most of their reasons, which you can see here (some of the reasons, such as radioactive waste, is different between fusion vs fission): www.powermag.com/blog/former-nuclear-leaders-say-no-to-new-reactors/
I think there is a difference between whether nuclear fusion is a feasible source of energy and whether nuclear fusion is a feasible career choice. Given the amount of private capital interest in this I can't imagine you'll struggle to make a living in this field.
@@chengong388 It falls into the "cool" category that is fun to learn about. Whether or not it's practical is up to Helion to prove. Thus far no Fusion Power Plants are practical so by your logic we just shouldn't make videos about fusion. It's the investors problem to not rely on only youtube videos to decide where their money goes. "Scam" is also a funny word here, considering most startups like this go bankrupt, sending most of the money into the void. Not a lot of it will be personally held by any one entity
@@Mallchad No it doesn't, there's nothing cool or fun about a scam disguised as engineering. Helion won't prove anything because it doesn't work even on a theoretical level, there's many very basic problems every scientist in the field knows, but Helion does not even acknowledge them never mind has a solution for. There's a difference between a genuine engineering startup, that may or may not pan out, and a scam: -The scam does not work even in theory, they rely on the investors not knowing the science, so they won't know the fact that it doesn't work even in theory. A real startup works on something that works in theory, and solve engineering challenges to realize said theory. -The scam aims to drag out the R&D phase for as long as possible, so everyone has a job and get paid their salary. A real startup aims to get the job done ASAP so they can commercialize the technology. At the end of the day, there's only one evidence you need to know that all these fusion power startups are scams. And that's the fact that they're spending so much time and money to build the ITER. If they weren't sure that this was the ONLY feasible fusion solution, they'd instead just invest in startups like Helion. But no, all the major governments pretty much only spend money on tokamaks, are they just stupid or what? I'd say it's far more likely, that all the top scientists have a consensus that this is the only path to fusion energy.
@@chengong388 You are way too emotionally invested in this topic IMO. I literally only care about the Real Engineering videos from a technology standpoint, to see what's possible, what can be build. Doesn't really matter to me if it helps the world or not, that's seperate. Government funding priorities doesn't mean anything. They spend billions and trillions of dollars on nuclear weapons but barely spend a dime on solar power and house infrastructure. If you *knew* the topic you should know that the a good portion of fusion companies are publically funded and lots of reactor types have been tried. Tokamak simply is *the most popular*, not best. popular. The stellarator is in theory better if you can waive the cost of manufactering. But you should know that. Of course. If you watched real engineering as anything other than loose and simplified educational material then I don't think that channel is for you
"The burden of proof is not on me, to disprove someone." So if I claim that you are wrong about helion, then by your logic it's not my job to prove it, but yours. You really seem to bend and turn everything so it fits your own needs and comfort. But I guess you have to: Seen by the level of aggression you are showing you probably know you are wrong or at least don't know any better.
Pretty sure this is a 3 hour vid addressing many of the huge technical issues Helion has to deal with, I don't think he is out to disprove them, but to show the technical issues that fusion has to overcome, some of these issues Helion have yet to address, so the burden is infact on Helion to address these issues, when they do, I'm sure we will see another video
Please speak in complete sentences! Much of the conversation is unintelligible. Um uh oh and so on anyway so you know blah yeah you so uhh,mm a ummm a a you know unh and this um you know just saying you know.
@@ImprobableMatter Until we have 3+ hours of unscripted detailed information and on-the-fly thinking from Dan S, I don't think you should be concerned about his criticism. You're a physicist, not a TV presenter.
Video contents by timestamp:
00:06:40 - Introduction
00:15:05 - Reactivity problems for Helion
00:30:57 - Helion will have 14MeV Neutrons
00:43:50 - The problems with Neutrons
01:05:52 - Helion's difficulties with Neutron shielding
01:18:57 - Why tokamaks etc might be better
01:28:28 - Diagnostics issues/discussion
01:42:00 - Turbulence + issues with Helion simulations
01:55:14 - Fast ion issues for Helion
02:02:26 - Adiabatic energy conversion issues for Helion
02:18:33 - Miscellaneous discussion
02:30:00 - NIF recent results discussion
02:42:23 - Outlook for Inertial Fusion power
03:03:08 - UA-cam channel meta discussion
03:06:00 - Lattice fusion summary
03:09:40 - More meta + AI for fusion
This was an entire semester's worth of information wasn't it?
It is a lot, I must admit. In retrospect, the adiabatic cycle is probably going to be the most confusing out of everything.
1:09:00
😅 1:10:37
1:😊🎉
I fell asleep listening to UA-cam videos and now I woke up in the middle of this video and have absolutely no idea what it's about. Seems like a good video though
Same here I have no idea how I ended up here
Same here haha I’ve ended at 2:29:48 haha
1:59:03 for me lol
Same thx algorithm
Same here. It's 3:40am. 😂
Cringe... that's what I sound like when I can't edit the million breaths, "uhms" and "you know"s? 😵
I thought it sounded OK during the stream, but listening back the audio and my speaking manner is just dreadful. Sorry about that.
sounded like normal unscripted human cadence to me
it's not nearly so bad as you make it out to be - your own voice always sounds worse to you than to your audience 😊
nah, it didn't bothered me personally at all, the content was too engagementful to even notice that. Thanks for awesome presentation!
tbh you were absolutely fine
When you are on a topic your speaking manner is quite good and easy to listen to. Sometimes you looked at comments in between and it completely disrupted your sentences. I think some little structural changes to the Q&A format could keep the contend and the questions from interfering.
Anyways, I loved the commentary on how exactly Helion has to speedrun a couple of decades worth of fusion research to even get their equipment up to date.
Great discussion of some of the engineering problems of fusion systems. I wish the companies were more forthcoming about these issues. Mostly they either hand-wave or say nothing at all. Thank you!
if they were a scam they wouldn’t say anything. but also if they had a solution to say, the neutron problem of course they will keep that secret also.
Have to say, I definitely prefer your scripted videos. I do appreciate the nuance this presentation goes into, but your videos are a lot clearer.
Yep.
This was fantastic. I really hope you continue making more content. This chat was a nice way to provide deeper coverage than your higher production value slide-deck style videos. It's really nice to hear from someone who knows what they are talking about.
To be fair, while Tritium is very radioactive (decay rate), the beta decay energy of Tritium is very veak, in the KeV range, so the electrons coming off it will quickly slow down, provided they come from outside the body.
Consider the outcry over the release of a few grams of Tritium in waste water from the Fukushima plant. Helion intends to keep kilograms of it in storage. Note that this is much higher than a D-T plant, since that would basically be cycling it very rapidly, not storing it for years waiting for it to decay.
Thanks for the great presentation! As a student in a DOE neutron scattering facility, I think many people are underestimating the regulatory hurdles that come with radioactivity from neutron activation.
Also, I'm really curious about your take on general fusion. Their design seems to check a lot of your good-fusion-engineering boxes while being very different from a tokamak. Would you consider doing a video looking at their approach?
6:30 or so to start it.
Sorry I couldn't join. Thanks for the kind words. Try'n make it next time. Just to clarify, I definitely don't have a PhD, and I'm at LLE rather than NIF. Just a lowly optics engineer, lol.
Erratum #5: NIF was not, in fact, "having its lasers cleaned" that day.
@@ImprobableMatter I dunno, maybe it was! 🤣
@@ImprobableMatter Incidentally where did you watch that movie Девять дней одного года? On some streaming service? I can't find an english subtitled version anywhere.
@@Muonium1 Firstly, I there used to be a version with good subtitles on UA-cam, but it has been deleted. Secondly, I believe I have a DVD which also supposedly has subtitles, but I will have to dig that out. It's quite good; it's not satirical like "Strangelove", rather very honest and actually has good science.
@@ImprobableMatter For all the boundless loathing I have for Soviet socialist-communism, I have to say that I do have a near equal measure of respect for the quality and resourcefulness of their physics during that era.
This was really great, thank you for the stream !
I really appreciate this it was very informative. Next time you do a Q&A, can you please read the questions out-loud before answering them? Sometimes, I was not sure what criticism exactly you were responding to.
Sure. I will try to structure it much better if I do another.
why are we even building ITER or anything else until we have an idea how to solve the neutron problem?
That's the point - they're meant to test how components will survive against plasma and neutrons.
at around 1:04:30 you are comparing a required 10^25 neutrons to cover 10 square metres and shred it the same as those mirrors, with their estimated 10^18 neutrons per second. This gives you 10^7 seconds to get that many neutrons. But then for some reason you change your answer to 10^5 seconds, and say that it will take a day, whereas with these numbers it should be 100 days. Now, I'm not saying that any of these estimates are necessarily correct, and it's probably a lot worse, but just introducing factor of 100 errors in your simple calculations does tarnish the reliability of your general statements about how bad it would be. I think it's worth checking the calculations before making statements, not because the results are much different, but because it makes it appear more reputable.
Fair enough.
Opening with a SMAC quote? You sir are a gentleman and a scholar.
I didn't expect this to be kicked off with an Alpha Centauri Quote, but good taste!
Love, love it
Great video about the challenges of Fussion
I love how each problem is being broken to fully understand the issues moving forward
Keep the good informative job !!
This is fantastic. Thanks for answering my question. I really love the deep, well through dives into these topics.
A lot of things (incl proofs of concepts for any fusion project) can only be revealed & clarified & adopted during live experimentations that's once first production size facility (v7 for "Helion Energy") will be built.
Regarding lattice confinement fusion, there was a UK company called Positron Dynamics that claimed something similar to NASA, well before them, using positrons from beta decay to induce fusion in a deuterium saturated lattice. A lot of their work was about slowing down the hot positrons.There are some videos around and even got a NIAC grant. The idea was to use it for propulsion.
If I remember correctly, they used the beta positive decay of a Krypton isotope and wanted to use the neutrons produced during fusion, to make more beta positive decay isotopes.
I haven't heard from them for a quite a while though, so maybe it's not working very well for them.
Amazing, this reappeared , after being zapped 🙂
~ 2:00:00 Adiabatic is the fast process and isothermic is the slow one, aren't they?
Yes, though watching the video back, I probably was very confusing with the description of the adiabatic part.
Good stream, I think very fair discussions and descriptions of the challenges. Donating to keep this kind of content coming! Maybe I can join on the next stream and ask about p-B11 reaction concepts if you're interested given the economics might be more workable.
Thanks. I didn't know it was possible to donate money outside a livestream superchat.
@@ImprobableMatter Apparently it is, called a Super Thanks. I don't see the option on all channels.
Thank you. This was good. I liked the long format.
I think it's safe to say that the only thing this channel has in common with Thunderf00t is a slight similarity in speaking voice. Thunderf00t main argues from a perspective of ignorance and has very little understanding of how the engineering process work e.g. criticises prototypes for being prototypes.
Thank you for taking the time to do this stream. If you do another Q&A (I hope you do) it would be great if you had better audio for your friend, I found them quite hard to hear / understand.
I wish this video had time stamps where specific questions were asked and answered.
I'll try and get some out.
@@ImprobableMatter It's actually a lot of work and time consuming. The longer the video the more time consuming it is.
Done.
@@ImprobableMatter Thanks.
For the AI related question that you answered at 3:10:50, you did briefly touch on AI-driven design, but then focused more heavily on uses of AI for solving operational control problems. I generally agree with your "no silver bullet" comment; most people thinking that way don't have a firm understanding of the subject.
In the case of AI-driven design, it's less about "machines being smarter than human designers", and more about "machine having the processing throughput to manipulate designs that are orders of magnitude more complex than human brains can manage". Humans are strategically brilliant and can make it very far by simplifying designs to the point where they are comprehensible by our relatively slow brains (to grossly oversimplify, very little in our brains moves quicker than 100Hz). The AI-optimized mechanical designs typically find savings by producing complicated flowing geometries that appear almost organic in style. In a crude sense, the difference between AI-optimized vs human-oriented designs is analogous to the stylistic difference between the complex Stellarator geometry versus the more regular Tokemak geometry -- and I suspect this observation may have inspired the question you were answering.
In the case of optimizing a Stellarator, to predict the degree to which AI-driven design optimization would help, I'd need to have experience grappling with the Stellarator optimization trade-offs, to know the extent to which competing trade-offs interact in such a way that increased complexity can deliver improvements in the performance metrics. In other words, AI won't help if it's the case that the seemingly complex Stellarator shape is actually rather regular (eg, a consistent degree of twist from coil to coil), and if there's very little optimization incentive to mutate that shape. On the other hand, if there are a lot of interacting considerations and a vast potential design space, then maybe there's more headroom. It might also be interesting to open up the design space by disaggregating the coils into a messy spaghetti of individual wires that can wrap the reactor at more than one angle rather than all loops from the same wire being parallel. Again, I'm not qualified to say where the Stellarator design headroom lives, or how much might exist; I'm just giving examples of the kinds of design changes that an AI-driven optimizer could explore.
Such AI-driven designs are intrinsically more challenging to fabricate, and for mechanical designs, depend heavily on being able to leverage digitally controlled additive and subtractive manufacturing techniques (eg 3D printing). One of the challenges of applying such techniques to a Stellarator would be the increased assembly cost. You might need a custom robot to lay the wires in a wildly complex geometry, or you'd have to have people following incredibly detailed instructions that resemble the (very expensive) custom-cut carbon-fiber hand-layup work done for turbofan blades ($20k per blade). And then the design would be highly brittle / difficult to change / difficult to repair. And it might be exponentially more difficult for the physicists to model (this alone might be a deal-breaker?). AI-driven design optimizers can of course incorporate fabrication constraints or estimated fabrication costs into their optimization goal function, but such constraints would need to be expressed formally rather than simply being designer intuitions and getting that right might take several iteration cycles between the physicists and their AI collaborators.
I don't know if this has been explored or not, but the first step would be to prove that there's enough optimization headroom to matter by producing a theoretical design that boosts the predicted optimization parameters (confinement time? field strength?) by a material amount, without worrying too much about whether or not the result is practical and buildable. If you can't produce a predicted win even from an unbuildable design, then there's no point in worrying about the practical problems. But if early exploration demonstrates large potential headroom, then researchers could explore constraining the AI's design space such that it can produce a good compromise design that boosts the optimized goals as much as possible, while still being constructible and practical enough on the other figures of merit (maintainability, repairability, modularity, etc).
Everything above is my mental model as someone familiar with training AI systems. My question to you is to answer what I cannot: does your instinct say that the Stellarator design shape could be improved via increased complexity? Can I (or an AI) take the existing design, and find incremental improvements by tweaking some of the coil shapes? Or is the design already close to optimality given present materials constraints, and the only thing that would help is a gross improvement, such as stronger superconducting magnet coils, or an increase in scale? What does your intuition say on this?
Wish I'd known this was a live qa
I just took plasma physics & fusion reactor design principals at UMich. Going to take take the part 2 and grad lab soon. So i have a lot of questions.
A lot of the helion guys went thrift this program, for better or worse.
Absolutely great conversation, thank you very much.
Ok so the first graph shows the amount of temperature produced which is not how Helion's reactors generate energy. They are not trying to heat up water to turn a turbine, temperature is not relevant to them.
I thought real engineering explained it well but looking at the responses you got I can see that few understood and argued on your terms based on your misunderstanding. Its this part of the video ua-cam.com/video/_bDXXWQxK38/v-deo.html
This is not the temperature produced. This is the temperature required for the rate of reactions to be
This is highly enjoyable to listen to such a discussion, I applied to work as an apprentice at JET a long time ago but was unfortunately not successful due to the IAEA. Still find the subject interesting. Hard problems are fun
Question: What prevents Tokemak (or Stellarator) designs from increasing the field strength by simply using more turns of magnet wire? In other words, today the magnet coils wrap around the reactor N times to create some field strength B. What limits designers from scaling this to wrapping the reactor 2N or 10N times? Or equivalently, putting a second coil surrounding the existing coil? The outermost coils would have a wider diameter, so IIUC, would be less efficient at contributing field strength, but presumably they would still be helpful.
Or are the designs already physically constrained, such as by the space to run wires through the center column?
Or is there a more subtle magnetic constraint that I'm not aware of?
Or maybe it's just a cost limitation and rather than doing as I suggest, they'd rather spend the equivalent funding increase scaling up to a large Tokemak (ie, scale everything together).
One might think that a superconductor would have anywhere up to infinite current for a given voltage, but there is a maximum magnetic field at which they no longer work. Also, really huge fields would put enormous mechanical stresses on the machine.
I appreciate that you aim to use less rude notes on your words. Gasoline is more reactive than jet fuel, but jet fuel have more energy per reaction. I think that's a better analogy
Fair enough. Imagine I compared 1MJ worth of rocket fuel to 1MJ worth of sunflower oil. Same energy, different rates of release.
@@ImprobableMatter yes because you need more sunflower oil molecules. Gasoline is high (energy) density high reactivity, and jet fuel in comparison is even higher density but low reactivity. while cooking oils have low density and low reactivity.
Could you go over "Catalyzed D-D + D" fuel cycle in your next video?
Yes, I'm sorry I didn't have time to go over your questions; they were in the slides, but after Helion and NIF.
@@ImprobableMatter Could we have a stand-alone video like your normal ones, on the topic? Also, can you tell us the number of barns and eV for that reaction? And from what I understand He3 does react with itself, would that be also a part of the "Catalyzed D-D + D" fuel cycle?
"Prove them wrong or be ignored" writes a person who is clearly not ignoring your videos.
Thank you for your detailed presentation. I have to wonder if the Helion approach of electricity generation by driving the magnetic flux out through the coils via the expanding plasma can be done with decent efficiency. Decades ago, people pursued magnetohydrodynamic generators as an alternative to traditional turbines driving traditional electromagnetic generators. I think these efforts failed because the combustion gasses could not be made sufficiently conductive to achieve good efficiency. Also, people have built explosive generators to produce very high pulse electrical power, but these generally expand a good conductor such as a copper cylinder to efficiently drive the magnetic flux through the coil. In the Helion process, how much of the flux can the plasma drive out? How much of the energy escapes as heat and neutrons in the process?
Regarding your graphic for the National Ignition Facility, extrapolating to a net electrical gain of 10 MJ per shot: 10MJ is about 2.8 kWh of energy. I am paying about 12 cents per kWh (retail price for electricity delivered all the way to my home). So, the energy from a shot is worth about 33 cents delivered. Perhaps the generating facility could be attractive if it could produce the energy at half that cost, or about 16 cents per shot. Suppose the diamond spherical shell for the fuel could be eliminated as well as the hohlraum, and the lasers could simply impinge directly on cryogenically frozen fuel pellets. Do you suppose the tritium-deuterium pellets could be produced at a cost of a few cents each, given that the facility would consume 864,000 pellets in a day of full operation at 10 shots per second? If we ignore the window material darkening issue, how many shots can be done before the laser window surfaces in the reaction chamber must be cleaned due to deposition of materials liberated from the chamber walls and equipment in response to the bombardment of the reaction products? The energy released in each shot presumably ends up as heat in the chamber walls. Given the size of the chamber (about ten meters in diameter) to stand up to the ongoing mini-explosions without fatigue, it would seem to be thermodynamically difficult to capture the heat at high enough temperature to achieve any conversion efficiency to electricity approaching 60%, let alone maintaining laser beam aiming accuracy to within a few tens of micrometers or better to assure uniform implosion. It is presumably very difficult to recycle the energy dissipated in the lasers themselves and that energy presumably ends up as additional waste heat (unless the facility is in a cold climate where the waste heat can be used for other purposes.) I'm just trying to say that a facility with net electrical energy gain may still be a long way from a commercially viable energy generation facility.
In principle, energy from the expansion of Helion's FRC could be recaptured as efficiently as the contraction. However, energy would be lost as bremsstrahlung, due to turbulence and the energetic particles produced by fusion with relatively large gyroradii. Also, they are going to be charging capacitors, which would have to remain efficient at high rep rates, working for months on end, and with the neutron/radiation issues I mentioned.
Could a laser direct drive scheme reach commercial viability? You raise very good points for why that would be a challenge. Certainly, if everything else were viable, pellet production costs would come down, but it's true - the final product cannot be made of gold or diamond or it will never compete with other power sources.
So this thing shoots plasma in, compressed, fusion reaction, shoot into a MHD converter, ok so Helion Energy’s reactor is being sound more like a glorified Z-pinch.
You showed a study on neutron-induced damage which used 0.01 MeV neutrons. And then said Helion would be dealing with much larger energy neutrons, implying that higher energy automatically equals more damage. But I thought the probability of a neutron interacting with a material (depending on the particular interaction process that is causing the damage) can be strongly dependent on the energy, and that for some processes, a high energy neutron is much less likely to initiate an interaction than a slower neutron.
Can you comment on this? Given some reasonably expected types of neutron damage (what processes can happen that cause neutron-induced damage to steel, copper, silicon, etc...?), will the neutrons being higher energy increase or decrease the probability of the underlying interaction processes?
You didn't even identify the particular process referenced in the study, and do a quick check to see if that process is more or less likely at higher energies. You just made a straight assertion that higher energy always equals more damage. Maybe it's obvious to you with more background knowledge than me on this topic, but it isn't obvious to me or probably most other viewers.
I motivated why they will necessarily have 2.4MeV neutrons and why they will almost certainly also have 14MeV neutrons. First of all, the exact effects of a huge neutron flux on technologically relevant materials is not well understood - this is why the rest of the fusion community are doing research as shown in Reference [6] from as recently as last year. The only certainty is that fast neutrons are bad news for the absorbing material.
Secondly, the study I showed (Reference [5]) had both thermal and >0.1MeV (potentially up to 2MeV or higher) neutrons. It is true that the absorption cross section is different for different energies, but eventually a fast neutron will collide and give up its energy (forget for an moment transmutation reactions) with part of the Helion machine. The more energy transferred, the worse it is for atoms which were previously sitting neatly in a lattice.
I think the neutron issue is more than anyone can think of. At least I haven't seen any comment mentioned the role of NRC. Since you are operating a power plant that emit radiation, you need to get approval from NRC before operation. Even if they do make it work and commercially feasibe, I am quite confident that they will never get pass NRC. NRC may take ten year to aquire the knowledge required to regulate this type of power plant. Then take another ten year to verify your design, material and operating procedure.
So several years ago I was at a bar with an employee from helion. In talking to him his opinion of the company and it’s goal was that the major problem was not the plasma physics, it was that the solid state power switching required to harvest the induced current in the magnets didn’t exist yet. So from him (at least this is my fuzzy and incomplete memory) they were already generating sufficient energy output, they just couldn’t harvest it. I don’t know if the power switching problem has been solved or if this adds to the conversation but it may be that the inefficiencies and limitations that you are worried about are solved but another practical issue is still limiting the overall technology
So I keep being on the side of "let's avoid neutrons", and as far as I understood that means proton-boron, right? So, if we figure out plasma confinement, what would be the limiting factor to temperature? The Bremsstrahlung? What if, in theory, we could harvest the power from Bremsstrahlung? Would the problem then basically be that the amount of energy dissipated by Bremsstrahlung is not related to the amount of energy created by fusion? And then the plasma would end up cooling down?
Yes, the problem would be bremsstrahlung, and the problem with the losses through it is that they would have to be recovered by steam turbines. Let's call the latter 50% efficient; if during a given interval of time you emit 100J of energy as bremsstrahlung, you have wasted 50J as heat. You must then make sure you are doing fusion quickly enough that you make back the wasted 50J. If you are extracting the fusion energy through steam turbines as well, then you have to make 100J. Numbers out of my butt aside, serious studies on this have concluded that this is hard.
@@ImprobableMatter Ohhh! So the energy balance would be reached by dumping the excess energy extracted back into the plasma. Which, both extracting energy from Bremsstrahlung and putting energy back into the plasma is inefficient currently. Got it, thank you!!!
P.S. The steam turbine efficiency is limited by the laws of physics, not technology. Look up a Carnot engine.
@@ImprobableMatter Yea, I know, but maybe in a few centuries we figure out how to make really efficient photovoltaics or something, I don't know 😃
Edit: Or is there a theoretical limit on those also?
Re: the adiabatic cycle - isn't the initial heating to 1MC and the fact the final plasma is at the same 1MC a good thing?
1. Heat plasma to 1MC
2. Magnetically compress plasma to 100-200MC
3. Fusion occurs heating plasma to much greater than 100-200MC
4. Expand of plasma and extract work (magnetically/somehow) back to 1MC plasma
5. GoTo #2
What am I missing? Is the plasma at #4 an "exhaust" carrying away the energy put in at #1 so #5 becomes "GoTo #1"?
My point is that after #5, you have to cool it down to room temperature. Otherwise, you can't pump out the Tritium gas (discussed why that is bad) and add new fuel. In any case, the way they described it, it will hit their divertor and cool anyway.
Thanks for replying. I didn't pick up that point. I jumped to the adiabatic time stamp after reading a comment.
Very good point: fusion Neutron/MeV is 1/20 vs 1/72 for fission … so any RFC using this fuel will produce “a reactors worth” of radiation ie
if u got to supply 250MeV then u got lots of coulombs of fast neutrons ❤ great point bro
In terms of optimization of stellerator designs, I would think that a genetic algorithm is what you would want to use as opposed to any sort of AI.
Genetic algorithms are a sub-set of AI. Or at least they were when I was studying it (some decades ago). Perhaps you meant to say "as opposed to any other kind of AI"?
Nice to see you corrected some of your factual errors. Good video.
To be clear, there were no factual errors in my response to your video.
I think the Q&A was better than the original video and had a nicer tone too (at least in the parts that I was there for).
I talked to David Kirtley about your argument about T- scattering and disruptions. He says, he might put together something for the FAQ if they have the time. Their electron temperature diagnostic was vetted on TFTR, btw. They also measure the plasma pressure on all locations. They also have the usual standard diagnostics for FRCs that have been vetted on every FRC program since. Overall, their diagnostics should be better than NIF.
The disruptions argument has been brought before but they have not materialized over 6 programs that went all the way to 10 keV today. I think it is unlikely that disruptions will suddenly appear at 20 out of nowhere. But what do I know?
The original video though... Oh come on! Just the part about "Helion promising a working power plant by 2021" is easily debunked as a factual error and quite frankly really unfair. It even says on the same page that you quoted (and show in the video) that they were looking for funding! They did not have the funding until very recently.
No bucks, no Buck Rogers!
Most of the other points are either not applicable or lack context, etc.
I think you are a really smart dude, who does know a lot. So I will say again, that I am extending my offer to have a serious debate about this, if you actually want that. I can (likely) get you answers to questions if you are interested.
@@elmarmoelzer2229 I didn't talk about disruptions, I talked about turbulence and fast ion losses, both of which CYGNUS does not and cannot simulate directly. Also, neutron embrittlement of their machine, their inability to pump out trace amounts of tritium with 1+Hz duty cycles leading to 14MeV neutrons and the inability of plasma below ~100eV to be used in the adiabatic cycle, hence that energy is unrecoverable. A few other things as well.
If anyone wishes to explore the non-factual errors made in the original video the reddit post in r/fusion contains a good discussion
@@ImprobableMatter /r/fusion disagrees
The probability of them bumbling into each other is 100% because like particles repel each other.
At 2:58:42, you claim that any commercially sized pulsed ICF approach (ex. >4000 MW) must fire multiple times per second. You reasoned that slower pulsing requires larger yields to produce the equivalent amount of power, and, by analogy to high-explosives, “nothing could survive a ton of TNT.” However, TNT is a chemical explosive. Most of the energy in DT fusion goes into the 14.1 MeV neutrons which penetrate several centimeters before thermalizing. Compared to chemical explosives, which are millions of times less energetic than nuclear reactions, a DT fusion reaction of equivalent energy (m*v*v/2) would produce thousands of times less outward directed momentum (m*v). Hence, it could easily contain much higher yields. Does this make sense?
Fair enough, but the near-instantaneous energy absorption is still difficult to handle and there is a limit. The target chamber at NIF is 10 meters across and is supposedly limited to a maximum yield of 45MJ only, see page 4 of the following: www.osti.gov/servlets/purl/15006532
Momentum aside, I think regular cyclic loading of a tonne of TNT of energy released in nanoseconds is out of the question for a practical facility.
@@ImprobableMatter OK, but NIF is not a commercial power plant, so it is not a good example to use for determining the maximum withstandible yield of a commercial power plant. NIF does not protect its optics from the intense neutron/x-ray pulses or flying debris, so damage accumulates each time a target is ignited. In that light, I understand the 45 MJ maximum yield you quoted. A more robust example (closer to the maximum) can be found in Freeman Dyson’s analysis of The Orion, a nuclear pulse rocket designed for missions to Alpha Centauri, the nearest star system to the Sun. His 1968 paper "Interstellar Transport" (Physics Today, October 1968, pp. (41-45) suggests how to fly city-sized spaceships by detonating megaton-sized deuterium fusion explosions in their proximity. For a less extreme example, in PACER revisited, R. W. Moir discusses an idea to generate electricity by detonating 2kt hydrogen bombs in an underground cavity lined with steel. His idea uses molten salt (FliBe) to absorb the neutrons and x-rays. Does that make sense?
@@michaeldeeth811 Yes, the idea of making energy by detonating thermonuclear bombs is not new. It would simply not commercially viable. These are old speculative paper studies and NIF is engineering reality. If you want to extrapolate to a practical powerplant, I would suggest the latter and not the former.
@@ImprobableMatter In clarification, I was not advocating for PACER or Orion. They were used as counterexamples, opposing the 45 MJ maximum yield boundary you imposed on ICF. It is ironic that you called NIF an example of non-speculative engineering. NIF was an extremely speculative design, two orders of magnitude beyond NOVA (at that time the world’s largest laser). Anyway, I started this thread because you said commercial IFE requires multiple shots per second. You based that on a maximum yield limit, stipulated to be 45 MJ. Do we agree that the 45 MJ maximum yield stipulation, applicable to NIF's unprotected optics, is not suitable for IFE in general? If so, the statement about IFE requiring multiple shots per second is unjustified. Am I making sense?
@@michaeldeeth811 I'm happy to lift the 45MJ limit by maybe an order of magnitude, but not the stipulation that IFE requires at least 1Hz rep rate to be practical. Not because I think I'm super clever - far from it - but because this is the consensus reached by scientists in the field, for the reasons I described.
1m water shielding is equivalent to 10cm of lead shielding. Isn't that enough?
You could certainly fiddle with different materials to optimize the neutron shielding, but at the end of the day (A) Helion's current design does not leave enough room to shield the coils; (B) the plasma-facing material will become churned up and retain Tritium therefore making it radioactive and contaminating the D-3He plasma with a producer of 14MeV neutrons.
Dots in a jell of clear liquid shape to the densities around themselves when you are pushing them to a 90 degree bend and then another one will change the way you think about what is happening
Please reupload the Thuderfart busting video, that guy really deserves more debunking since he is becoming kind of a cult leader.
Awesome stream, very interesting content, glad to hear professional and realistic take on fusion. IDK, but I feel in the gut (or rather ass) that NIF has the highest probability of success, just due to the fact that military also benefits that. Sounds like the same story like with fission :)
Mh not sure about that, being military funded, they focus on simulating what would happen in a fusion bomb (geometry and stuff).
They could get already much better fusion yields, but they'd have to reconfigure all the lasers, which wouldn't benefit the military, so it isn't going to happen
NIF has zero chance of success. None. 0.00000% chance. In order to generate electricity as a power plant commercially, they need to fire several times in a seconds. They can manage only one or two per day. The target pellet needs to be manufactured perfectly and aligned perfectly. How can you load a pellet several times a second with nanometre precision? It won't scale. Thus it is just a scientic experiment and with great military value. Remember the name, National Ignition Facility. Ignite what? Hydrogen bomb, men.
found after Sabina and I pray you make more videos. please and thank you
It would be great to know your full name and CV. Thanks for your excellent efforts.
A video titled "What This Breakthrough Means for Nuclear Fusion" by Undecided with Matt Ferrell, shows that 200MJ of power created 2.05 MJ of Laser energy, from which 3.15 MJ of fusion energy was produced at the NIF.
That's great. It does work. Thermonuclear bombs work too. However, it's no where near practical. The physics says it can be done in a myriad of ways but the engineering needs to close that gap before there any hope of a functioning reactor. Personally, my favorite idea is liquid metal cavitation because it's the neatest engineering setup. Nothing but NIF has been demonstrated but NIF is never going to be a practical method by its very design. A completely different idea which borrows its concepts might work.
I love your content but I think you are being way too "fair".
There is a whole economics around startups and venture capital. The real purpose of many startups is to get bought out by someone bigger - so the founders become rich. Similarly Venture Capitalists may not care about the longevity or practicality of a startup - they care if the startup will attract more investors so they can sell their share and make money. The entire financial industry is built on trends and speculation on those trends. The long term sustainability is irrelevant.
As to Real Engineering - the guy has 3m subscribers but its all "The Insane Engineering of the !!" - clickbait for people who can't tell the difference between science and science fiction. Looking at the video its pretty much an uncritical promo. To be fair that is how science is mostly reported across the MSM.
Its incredibly sad that well researched well explained factual info get trumped by marketing drivel.
BTW, doesn’t that guy realise that tokamaks could use direct energy converters as well, such as nipping electrons from the plasma donut and run it through a inverse cyclotron converter.
Wait did you say it may be the case you're a 15 yo? Damn
Great video. Thank you
There’s all this talk that “with a liter of heavy water we could power Boston for 100 years”. Can u help me understand or point me to something that would explain how much fuel is in the chamber? do they inject the fuel once then let the machine run? How much fuel? Is there a limit on how much fuel? This would be for a tokamak
Also, what is the number 1 obstacle to self sustaining fusion? Magnets? Metals? Product?
If we had magnets that held temperatures of 600 million, could we go straight to the next problem?
Or is it the plasma drift problem? Where the plasma seeps outside the field?
fantastic. please do more!
I've read some comments to this video claiming they prefer your scripted ones, mainly because those are easier to follow.
In the case of the critique of Helion's claims/ideas/machines I have to disagree, this one is much better. In my opinion, reasoned, well informed criticism is always better than rushed derision. This one sounds a lot more like scientific debate, less "ranty".
Here you offer a number of interesting, reasoned points that were not that well argued/justified in the previous one. Pity this only has 1/50 the number of views. Maybe translate this one into a script for a shorter, clearer, third try ?
P.S. Given the increasing number of startups in the field of fusion power, someone with the required knowledge could start a series of scientific critiques of them. Just saying. 😉
Maybe a live, but much less hectic, rundown of them?
Perpetual motion. Fusion reactor. Quantum computer. They're all comming soon and all together
You definitely could use vegetable oil as rocket fuel. You do know RP1 is pretty much just deisel fuel right? High enough amounts of oxygen will make steel burn like a rocket fuel
Hi loved the video!! Im so glad the recording was saved!. Best Bday present ever. Love your content keep up the amazing work
Great technical discussion. Too many "you know" ;)
The gun analogy is not particularly helpful, a fusion powerplant is only producing and absorbing energy at comparable levels to a non fusion plant in a gas turbine we might be putting 200MW of heat energy into a combustor that would fit in a coffee table.
To further elaboration on the shell analogue. Shells are specifically designed to produce a damaging effect in a way that is difficult to mitigate. They contain the explosion in such a manner that it transfers energy to solid projectiles, the shell can penetrate targets so that the explosive pressure can be used to split solid objects. A more reasonable approximation would be the gun itself. In that context explosions may be contained in the breach and provides you provide adequate cooling a high rate of pulsed energy depositions can be contained.
Yes, but my point is the cyclic nature of it. For any proposal, ask yourself: can all the systems cycle at the proposed frequency? Lasers, electronics, pumping, capsule injection, capsule manufacture etc... In principle yes, but not so easy. My two cents are at the end of my inertial fusion discussion: ua-cam.com/video/mxmxZI2Ltvs/v-deo.html
I… DECLARE… FUSIOOOON!
I completely disagree with you on the nature of Thunderf00t. His videos have been fairly reliable as a whole and so far none of them have ended up contradicted by reality. The only one I think is slightly off the mark is the idea batteries can't get much better than they are, even theoretically sulfur batteries would be better than lithium if we can find a way to make them stable, but as a whole none of them has been inaccurate. I will say his old feminist and creationist videos were crude, but saying it's "splitting hairs" is a pretty bold statement when the creationist videos are literally a mirror of what philosophers have been saying for the last 2000 years and very few people have agreed with be vocal modern feminists (to the point all of them from the time he made those videos have become irrelevant). But most of his videos go directly into the math on why the claims made are untrue. That's about as reliable as your argument could be.
The most I could find that could be argued is a reddit post about his Space X videos, though the retorts aren't any less hair pulling than his and a few contradict other arguments they made. There's only one claim of his that was wrong and it's more because Space X said it themselves internally. They sent emails saying if they couldn't find a way to reuse the same rocket every 2 weeks they'd go bankrupt. In reality neither happened, they never got relaunches that fast nor have they gone bankrupt. Though they did raise launch prices and have been receiving grants from the government so that's more likely why they believed such.
Yes
Heh. Trying to talk to fusion fanbois is like talking to MSR fanbois referencing Oakridge.
Fusion will get worked out but the when is an unknown even with the half dozen different concepts out there where the maths but only the ideal maths checks out.
I want to study nuclear fusion in college, is nuclear fusion feasible? Is what I am trying to do a waste of time?
If I can't make a living doing nuclear fusion research, I plan to join another university where I can make good money.
Is there a future for nuclear fusion research?
how is anybody suppose to know for sure? theyre still working on this... what im pretty sure about is that it will take more than one man and many metric tons of money to get it done... so yeah somewhere in there there is room for you as well... it will look something like a stadium shot but it is what it is
I think you should consider transferable skills and personal growth more than just "where I can make good money".
imo fusion will stay around for research for a long time but its not what I'd call "stable". You might move jobs quiet a lot depending on where you go.
ITER will be around for a long time for example.
Just in general if you're good enough to be a Fusion Nuclear Physicist or Engineer you can do ALOT more in any other topic you please.
And a good understanding of engineering and/or physics makes good foundational knowledge for other things.
Say, aerospace and silicon.
You can make a living doing anything, and Dennis Whyte's discussion on the industry of fusion research with Lex Fridman indicates that there will be an increasing desire for fusion reactor engineers and scientists going into the future. We can do nuclear fusion research, and its interesting and important to a lot of parallel human endeavours.
This question, however, often is conflated with "can we do nuclear fusion in a plant on earth such that it generates power on the order of GWs into a cities' electrical grid AND so that it is competitive on the energy market".
This, unfortunately, is not really guaranteed. It's possible that this is the equivalent of building a space rocket to get you from your home to your school. It might generate more force and do the job faster, but the technological complexity and scale required to simply get it to turn on might be so beyond what you actually need. So that may mean that every power plant costs ten times what a fission plant would cost, and 100 times what solar/wind and other sources would cost even with scaling economics. Its highly doubtful that nuclear will be a significant component on the switch from hydrocarbon energy sources anytime soon, as reiterated by a number of nuclear regulatory leaders. I would assume this includes fusion for most of their reasons, which you can see here (some of the reasons, such as radioactive waste, is different between fusion vs fission):
www.powermag.com/blog/former-nuclear-leaders-say-no-to-new-reactors/
I think there is a difference between whether nuclear fusion is a feasible source of energy and whether nuclear fusion is a feasible career choice. Given the amount of private capital interest in this I can't imagine you'll struggle to make a living in this field.
@@dangerousham3519 This, essentially
people need to unsubscribe from Real Engineering ASAP, they're now constantly making videos for these kinds of scam "engineering" startups.
So?
It's a channel about cool engineering and technology concepts and practical physics/engineering.
It's not for investors
@@Mallchad but it's not "practical" is it? Also, what essentially are movie stage sets, to scam investors, are not "cool".
@@chengong388 It falls into the "cool" category that is fun to learn about.
Whether or not it's practical is up to Helion to prove. Thus far no Fusion Power Plants are practical so by your logic we just shouldn't make videos about fusion.
It's the investors problem to not rely on only youtube videos to decide where their money goes.
"Scam" is also a funny word here, considering most startups like this go bankrupt, sending most of the money into the void. Not a lot of it will be personally held by any one entity
@@Mallchad No it doesn't, there's nothing cool or fun about a scam disguised as engineering.
Helion won't prove anything because it doesn't work even on a theoretical level, there's many very basic problems every scientist in the field knows, but Helion does not even acknowledge them never mind has a solution for.
There's a difference between a genuine engineering startup, that may or may not pan out, and a scam:
-The scam does not work even in theory, they rely on the investors not knowing the science, so they won't know the fact that it doesn't work even in theory. A real startup works on something that works in theory, and solve engineering challenges to realize said theory.
-The scam aims to drag out the R&D phase for as long as possible, so everyone has a job and get paid their salary. A real startup aims to get the job done ASAP so they can commercialize the technology.
At the end of the day, there's only one evidence you need to know that all these fusion power startups are scams. And that's the fact that they're spending so much time and money to build the ITER. If they weren't sure that this was the ONLY feasible fusion solution, they'd instead just invest in startups like Helion. But no, all the major governments pretty much only spend money on tokamaks, are they just stupid or what? I'd say it's far more likely, that all the top scientists have a consensus that this is the only path to fusion energy.
@@chengong388 You are way too emotionally invested in this topic IMO.
I literally only care about the Real Engineering videos from a technology standpoint, to see what's possible, what can be build. Doesn't really matter to me if it helps the world or not, that's seperate.
Government funding priorities doesn't mean anything. They spend billions and trillions of dollars on nuclear weapons but barely spend a dime on solar power and house infrastructure.
If you *knew* the topic you should know that the a good portion of fusion companies are publically funded and lots of reactor types have been tried. Tokamak simply is *the most popular*, not best. popular.
The stellarator is in theory better if you can waive the cost of manufactering. But you should know that. Of course.
If you watched real engineering as anything other than loose and simplified educational material then I don't think that channel is for you
So the source of the problem was trump’s deregulation and corporate greed. Sounds far right to me.
"The burden of proof is not on me, to disprove someone."
So if I claim that you are wrong about helion, then by your logic it's not my job to prove it, but yours.
You really seem to bend and turn everything so it fits your own needs and comfort. But I guess you have to: Seen by the level of aggression you are showing you probably know you are wrong or at least don't know any better.
Pretty sure this is a 3 hour vid addressing many of the huge technical issues Helion has to deal with, I don't think he is out to disprove them, but to show the technical issues that fusion has to overcome, some of these issues Helion have yet to address, so the burden is infact on Helion to address these issues, when they do, I'm sure we will see another video
If you disagree with improbable matter you are attacking science itself
hi
Hello there!
@@tricky778 general Kenobi
Fusion power is NEVER. GET REAL AND STOP LYING
Please speak in complete sentences! Much of the conversation is unintelligible. Um uh oh and so on anyway so you know blah yeah you so uhh,mm a ummm a a you know unh and this um you know just saying you know.
Totally agree - I watched this back and it was dreadful.
@@ImprobableMatter Until we have 3+ hours of unscripted detailed information and on-the-fly thinking from Dan S, I don't think you should be concerned about his criticism. You're a physicist, not a TV presenter.